Chrysanthemum plant named ‘Yohamilton’

ABSTRACT

A distinct cultivar of Chrysanthemum plant named ‘Yohamilton’, characterized by its upright and uniformly mounded plant habit; freely branching, dense and full plants; vigorous and strong plant growth; strong and dark green leaves; uniform flowering; excellent inflorescence form retention; early flowering, eight-week response time; large and full decorative-type inflorescences that are about 9.7 cm in diameter; bright yellow-colored ray florets; excellent winter performance; and excellent postproduction longevity with inflorescences and leaves maintaining good substance and color for about three to four weeks in an interior environment.

BACKGROUND OF THE INVENTION

The present Invention relates to a new and distinct cultivar ofChrysanthemum plant, botanically known as Dendranthema grandiflora andhereinafter referred to by the cultivar name Yohamilton.

The new Chrysanthemum is a product of a planned breeding programconducted by the Inventor in Salinas, Calif. and Fort Myers, Fla. Theobjective of the breeding program is to create new potted Chrysanthemumcultivars with desirable inflorescence form and floret colors, goodsubstance, and excellent postproduction longevity.

The new Chrysanthemum originated from a cross made by the Inventor inJanuary, 1994, in Salinas, Calif., of a proprietary Chrysanthemumseedling selection identified as YB-6145 as the male, or pollen, parentwith a proprietary Chrysanthemum seedling selection identified asYB-1421 as the female, or seed, parent. The new Chrysanthemum wasdiscovered and selected by the Inventor as a single flowering plantwithin this population in May, 1995. The selection of this plant wasbased on its desirable inflorescence form and floret colors.

Asexual reproduction of the new Chrysanthemum by terminal cuttingsharvested in a controlled environment in Fort Myers, Fla., has shownthat the unique features of this new Chrysanthemum are stable andreproduced true to type in successive generations.

SUMMARY OF THE INVENTION

The cultivar Yohamilton has not been observed under all possibleenvironmental conditions. The phenotype may vary somewhat withvariations in environment such as temperature, daylength and lightintensity, without, however, any variance in genotype.

The following traits have been repeatedly observed and are determined tobe the unique characteristics of ‘Yohamilton’. These characteristics incombination distinguish ‘Yohamilton’ as a new and distinctChrysanthemum:

1. Upright and uniformly mounded plant habit.

2. Freely branching, dense and full plants.

3. Vigorous and strong plant growth.

4. Strong and large dark green leaves.

5. Uniform flowering and excellent inflorescence form retention.

6. Early flowering, eight-week response time.

7. Large and full decorative-type inflorescences that are about 9.7 cmin diameter with numerous ray florets.

8. Bright yellow-colored ray florets.

9. Excellent winter performance.

10. Excellent postproduction longevity with inflorescences and leavesmaintaining good substance and color for about three to four weeks in aninterior environment.

Plants of the new Chrysanthemum are similar in ray floret coloration toplants of the cultivar, Iridon, disclosed in U.S. Plant Pat. No. 6,125.In side-by-side comparisons conducted in Fort Myers, Fla., plants of thenew Chrysanthemum differ from plants of the cultivar Iridon in thefollowing characteristics:

1. Plants of the new Chrysanthemum are more vigorous and taller thanplants of the cultivar Iridon.

2. Plants of the new Chrysanthemum have larger leaves than plants of thecultivar Iridon.

3. Plants of the new Chrysanthemum have larger inflorescences thanplants of the cultivar Iridon.

4. Plants of the new Chrysanthemum flower about one week earlier thanplants of the cultivar Iridon.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying colored photographs illustrate the overall appearanceof the new Chrysanthemum showing the colors as true as it is reasonablypossible to obtain in colored reproductions of this type. Colors in thephotographs may differ from the color values cited in the detailedbotanical description which more accurately describe the actual colorsof the new Chrysanthemum.

The photograph at the top pf the first sheet comprises a top perspectiveview of a typical flowering plant of ‘Yohamilton’.

The photograph at the bottom of the first sheet comprises a close-upview of a typical inflorescence and upper (left) and lower (right)surfaces of typical leaves of the cultivar Yohamilton.

The photograph on the second sheet comprises a close-up view of typicalinflorescences of ‘Yohamilton’.

DETAILED BOTANICAL DESCRIPTION

In the following description, color references are made to The RoyalHorticultural Society Colour Chart except where general terms ofordinary dictionary significance are used. The following observationsand measurements describe plants grown and flowered during the Autumn inSalinas, Calif., under greenhouse conditions which approximate thosegenerally used in commercial potted Chrysanthemum production. Fourunrooted cuttings were directly stuck in a 15-cm container and pinchedonce. Plants used for this description were grown as disbudded-types.Measurements and numerical values represent averages of typicalflowering plants.

Botanical classification: Dendranthema grandiflora cultivar Yohamilton.

Commercial classification: Decorative disbudded-type pottedChrysanthemum.

Parentage:

Male, or pollen, parent.—Proprietary Chrysanthemum seedling selectionidentified as YB-6145.

Female, or seed, parent.—Proprietary Chrysanthemum seedling selectionidentified as YB-1421.

Propagation:

Type.—Terminal tip cuttings.

Time to rooting.—Seven to ten days with soil temperatures of 21° C.

Rooting habit.—Fine, fibrous and well-branched.

Plant description:

Appearance.—Herbaceous decorative potted Chrysanthemum typically grownas a disbudded-type. Inverted triangle; stems mostly upright andsomewhat outwardly spreading giving a uniformly mounded appearance tothe plant. Vigorous and strong plant growth; excellent winterperformance. Freely branching; about four lateral branches develop afterremoval of terminal apex (pinching); dense and full plants.

Plant height.—About 26 cm.

Plant width.—About 39 cm.

Stem description.—Diameter: About 3 mm. Texture: Pubescent. Color: Closeto 146A.

Foliage description.—Arrangement: Alternate. Length: About 9.1 cm.Width: About 7.8 cm. Apex: Cuspidate. Base: Mostly truncate. Margin:Palmately lobed, sinuses between lateral lobes mostly divergent.Texture: Upper and lower surfaces with very fine pubescence; veinsprominent on lower surface. Petiole length: About 2.6 cm. Petiolediameter: About 4 mm. Color: Young foliage upper surface: Darker than147A. Young foliage lower surface: Darker than 147B. Mature foliageupper surface: Darker than 147A. Mature foliage lower surface: Darkerthan 147B. Venation upper surface: 147A to 147B. Venation lower surface:147B.

Inflorescence description:

Appearance.—Decorative inflorescence form with elongated oblong-shapedray florets with long corolla tube, spoon-like. Numerous ray florets,full inflorescences. Inflorescences borne on terminals above foliage.Disk and ray florets arranged acropetally on a capitulum.

Flowering response.—Under natural conditions, plants flower in theautumn/winter in the Northern Hemisphere. At other times of the year,inflorescence initiation and development can be induced under shortday/long night conditions (at least 13.5 hours of darkness). Plantsexposed to three weeks of long day/short night conditions after plantingfollowed by photoinductive short day/long night conditions flower abouteight weeks later; early flowering.

Postproduction longevity.—Inflorescences and leaves maintain good colorand substance for about three to four weeks in an interior environment.

Quantity of inflorescences.—As a disbudded-type, all lateralinflorescences are removed to allow for maximum terminal inflorescencesize. One inflorescence per lateral stem; about four inflorescences perplant.

Inflorescence bud.—Height: About 7 mm. Diameter: About 8 mm. Color:Close to 137A.

Inflorescence size.—Diameter: About 9.7 cm. Depth (height): About 2.5cm. Diameter of disc: About 7 mm.

Ray florets.—Shape: Elongated-oblong, long corolla tube, spoon-like;concave. Orientation: Initially upright, then horizontal. Excellentinflorescence form retention. Length: About 4.4 cm. Width: About 9 mm.Apex: Emarginate. Margin: Entire. Texture: Smooth, glabrous, satiny.Number of ray florets per inflorescence: Very full, more than 300.Color: When opening: Green, 154A to yellow, 9A. Fully opened, uppersurface: Bright yellow, 9A. Fully opened, lower surface: 9B to 9C.

Disc florets.—Shape: Tubular. Apex: Serrated. Length: About 5 mm. Width:Apex: About 1.5 mm. Base: About 1 mm. Number of disc florets perinflorescence: About 57. Color: Immature: 154A. Mature: Apex: Yellow,9A. Mid-section and base: White, 155D.

Reproductive organs.—Androecium: Present on disc florets only. Anthercolor: 14A. Pollen amount: Scarce. Pollen color: 17A. Gynoecium: Presenton both ray and disc florets.

Disease resistance: Resistance to pathogens common to Chrysanthemums hasnot been observed on plants grown under commercial greenhouseconditions.

Seed production: Seed production has not been observed.

It is claimed:
 1. A new and distinct cultivar of Chrysanthemum plantnamed ‘Yohamilton’, as illustrated and described.